package com.wyix.service.impl;

/**
 * 无接口的VIP服务类（CGLIB代理普通类）
 *
 * @author wangdx
 * @since 2025/8/6
 */
public class VipService {
    public String upgradeVip(String userId, int level) {
        if (level < 1 || level > 5) throw new IllegalArgumentException("VIP等级必须为1-5级");
        System.out.println("用户【" + userId + "】升级到VIP" + level + "级");
        return "VIP升级成功，享受专属折扣";
    }
}
